An earthquake decimates a ground-squirrel population, killing 98% of the squirrels. the surviving population happens to have broader stripes, on average, than the initial population. if broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake?

directional selection
a founder event
disruptive selection
a genetic bottleneck

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

well first you need the sample of the temperature and gas level. i couldnt write a hypothesis unless i had some data. i think temperature changes will effect volumes of gas because gas changed into a solid or liquid at specific temperatures.